A powder spray gun, is usually used for powder coating, which is part of an apparatus including a control unit and a supply reservoir for the powder. The control unit permits manual voltage regulation of the high voltage generator of the gun by adjustment of a potentiometer, with the electrodes of the high voltage generator extending into the powder stream passageway in the gun and electrostatically charging the powder. The control unit further permits a manual regulation of the powder amount which the gun passes within a given time period. In front of the muzzle of the gun there is a deflection plate, which has the effect of deflecting and scattering the powder stream exiting from the gun muzzle, the spacing of the deflection plate from the gun muzzle determining the degree of deflection and scattering of the powder.
The use of presently available apparatus often is not economically feasible. For adjustment of the spacing of the deflection plate from the gun muzzle, the equipment must be shut off in order to permit the adjustment to be made manually. Furthermore, the regulation of the needed powder feeds and of the voltage of the generator is awkward, since each time there must be manual adjustment of the control unit, which can at times be relatively remote from the location where the gun is being operated.